[A case of hepatocellular carcinoma associated with autoimmune hepatitis and increased scintigraphy of liver accumulation].
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Autoimmune Diseases↗
Biomedical subjects
Y Mizuguchi
Publications and source records attributed to Y Mizuguchi.
Rifampicin resistance and mutation of the rpoB gene in Mycobacterium tuberculosis.
Using 39 clinical isolates of Mycobacterium strains with a broad range of susceptibility to rifampicin, we examined the relationship between the degree of resistance to rifampicin and mutational sites of the rpoB gene. All rifampicin-resistant strains had missense mutations. Twenty strains (95%) had a mutation in the cluster I region, which has also been reported in Escherichia coli [Jin and Gross (1988) J. Mol. Biol. 202, 45-58], and the remaining one strain had a mutation at codon 381 [Ala-->Val] in the N-terminal region, which has not been reported in E. coli. Among 18 rifampicin-susceptible strains, two had a mutation in the cluster I region and the other three strains had a mutation in the cluster III region. The mutations at codons 513 (5%), 526 (33%) or 531 (43%) in the cluster I region led to high level resistance to rifampicin (50 micrograms ml-1 < or = MIC). The mutations at the other sites, in the cluster III region (codons 679 or 687) and even in the cluster I region (codon 514, 521, or 533), showed low level (MIC = 12.5 micrograms ml-1) or no (MIC < 0.39 microgram ml-1) resistance to rifampicin. These results suggest that mutations in the rpoB gene are, mostly, but not necessarily, associated with rifampicin resistance of M. tuberculosis, and the sites of mutations on the rpoB gene will affect the level of resistance to rifampicin.
Amino Acid Sequence↗
Serous cystadenoma of the pancreas communicating with a pancreatic duct.
CONCLUSION: To differentiate serous cystadenoma from other cystic lesions communicating with the pancreatic duct, careful radiological examination is necessary. BACKGROUND: Communication between the cystic cavity and the pancreatic duct in an ordinary serous cystadenoma is uncommon, although it is not uncommon in other cystic lesions, such as pseudocyst, mucinous cystadenoma/adenocarcinoma, and intraductal papillary tumor. METHODS. A serous cystadenoma of the pancreas communicating with main pancreatic duct in a 76-yr-old male is reported. RESULTS: The communication was preoperatively demonstrated by endoscopic retrograde cholangiopancreatography and confirmed by histopathological examination of the resected specimen.
Aged↗
[Two case of Fitz-Hugh-Curtis syndrome with Chlamydia trachomatis infection].
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Adult↗
Ductal adenocarcinoma of the pancreas associated with intratumoral calcification.
An invasive ductal carcinoma of the pancreas with intratumoral calcification is reported in a 59-yr-old female. The calcification was preoperatively demonstrated by ultrasonography and computed tomography. On the cut surface of the resected specimen of the pancreas tail, calcification was observed in the central part of the ductal adenocarcinoma. Although calcification is not uncommon in chronic pancreatitis or serous cystadenoma, mucinous cystadenoma/adenocarcinoma, solid and cystic tumor, and islet cell tumor, intratumoral calcification is uncommon in an ordinary ductal adenocarcinoma of the pancreas. For differential diagnosis from other conditions associated with calcification, careful examinations are necessary.
Calcinosis↗
Modified cell-flow microchannels in a single-crystal silicon substrate and flow behavior of blood cells.
Previously reported cell-flow microchannels in a single-crystal silicon substrate (Microvasc. Res. 44, 226-240, 1992) have been modified, and flow behavior of blood cells is described using flow rate-time curves and video pictures. The principal structure (2600 identically sized channels in parallel) was retained to give the same simple quantitative measure of the total flow rate for blood cell suspensions under constant suction. Level areas (terraces) were placed at the entrance and exit sides of the parallel channels level with the channel depth (4.5 microns) so that blood cells just entering into and flowing out of the channels could be more clearly observed under reflecting illumination. Three lengths (10, 20, and 100 microns) of channel were used each with a terrace width of 30 microns. In agreement with calculated values, the resistance to flow at the terrace portion was shown to be nearly equal to that per 10 microns of the channel portion. Clearer pictures were obtained of channel blocking by activated leukocytes and platelet aggregates after addition of each stimulant. Erythrocyte aggregates showed easy transit even through the 100-microns-long channels and through narrow spaces, including gaps probably narrower than 2 microns, which were formed between plugging leukocytes at the terrace portion.
Blood Flow Velocity↗
2-Deoxy-D-glucose inhibits intracellular multiplication and promotes intracellular killing of Legionella pneumophila in A/J mouse macrophages.
Legionella pneumophila can grow intracellularly in A/J mouse macrophages. 2-Deoxy-D-glucose (2dG) (0.1, 1, and 10 mM) inhibited intracellular multiplication and promoted intracellular killing of L. pneumophila dose dependently when it was added to the culture medium of macrophage monolayers, whereas it did not inhibit the bacterial growth in buffered yeast extract broth, which was used for an L. pneumophila culture. The effect of 2dG was reversible because the surviving bacteria resumed intracellular multiplication after the washing away of 2dG from the culture. The effect of 2dG was also competitively inhibited by high concentrations of glucose. The inhibitory effect of 2dG was not attributed to the inhibition of bacterial phagocytosis by macrophages. Furthermore, sodium fluoride (0.1 and 1 mM), cycloheximide (0.1 and 1 microgram/ml), and tunicamycin (1, 2, and 5 micrograms/ml) did not promote the killing of L. pneumophila in macrophages, implying that the inhibitory effect of 2dG cannot be attributed to the inhibition of glycolysis, protein synthesis, and protein glycosylation in macrophages. We suggest that 2dG promotes intracellular killing of L. pneumophila by activating some novel killing mechanism of macrophages.
Animals↗
Direct evidence of neuron impairment by oral infection with verotoxin-producing Escherichia coli O157:H- in mitomycin-treated mice.
We developed a mouse model of acute encephalopathy induced by verotoxin 2 variant (VT2v)-producing Escherichia coli. Three-week-old mice were inoculated intragastrically with approximately 10(10) CFU of E. coli O157:H- strain E32511/HSC and simultaneously given an intraperitoneal injection of mitomycin (MMC; 2.5 mg/kg). Drinking water containing 5 g of streptomycin sulfate per liter was given ad libitum from 3 days before the infection. From 1 to 2 days after bacterial inoculation, clinical features including weight loss, weakness, and flaccid paralysis of the extremities developed, usually culminating in death within 4 days. Diarrhea was not observed during the course of disease. No mice died in the absence of streptomycin or MMC treatment for 2 weeks after the oral bacterial infection. Judging from the clinical course and the biochemical and histological examination, the cause of death was not likely to be attributable to renal failure or to a side effect of MMC. To better understand the cause of death, we examined the brain cortex and spinal cord of the moribund mice by electron microscopy. Mice showing mortal symptoms were given horseradish peroxidase intravenously. The tracer was present in the endothelial basal lamina, in the surrounding extracellular spaces, and even in the neuron fibers of the brain cortex. Furthermore, immunoreactivity of VT2v, proved by the use of rabbit anti-VT2 serum, was localized selectively in the damaged myelin sheaths of neuron fibers which were accompanied by edematous axons in the brain cortex and spinal cord. These findings strongly suggest that VT2v is toxic to both endothelial cells and neurons in the central nervous system and subsequently causes fatal acute encephalopathy.
Acute Disease↗
Analysis of the replication region of a mycobacterial plasmid, pMSC262.
We determined the nucleotide sequence of a DNA fragment which contains the replication region of pMSC262, a Mycobacterium scrofulaceum plasmid used to construct the Mycobacterium-Escherichia coli shuttle vector. The complete sequence of the fragment contained 2,504 bp with an overall G+C content of 69.8%. By deletion analysis, we found that the minimum length required for plasmid replication in M. bovis BCG was about 1.6 kb. Within this region, several open reading frames (ORFs) and a putative replication origin (ori) were identified by computer analysis. One of the ORFs, ORF2, which encodes a putative 28.9-kDa basic protein with characteristics of DNA-binding proteins, appeared to be involved in replication of the plasmid in BCG. By separation of ORF2 and the putative ori region, it was revealed that the relative locations of ORF2 and the putative ori region are likely important for replication in BCG. No DNA or amino acid homologies were found between this replication region and that of pAL5000, another mycobacterial plasmid used for vector plasmid construction. In addition, we found that this replicon did not lead to replication in E. coli and was compatible in BCG with pAL5000-derived vector plasmid pYUB75 (R. G. Barletta, D. D. Kim, S. B. Snapper, B. R. Bloom, and W. R. Jacobs, J., J. Gen. Microbiol. 138:23-30, 1992).
Amino Acid Sequence↗
Intracellular multiplication of Legionella pneumophila in HL-60 cells differentiated by 1,25-dihydroxyvitamin D3 and the effect of interferon gamma.
We examined leukemic cells, HL-60, an acute promyelocytic leukemia cell line, after differentiation induced by 1,25-dihydroxyvitamin D3 (D3) and retinoic acid (A) for infection of Legionella pneumophila, the etiologic agent of Legionnaires' disease. We investigated the effect of interferon gamma (IFN-gamma) on the differentiated cells and on the intracellular growth of the bacteria. An examination of morphological and antigenic changes in the cells was also included in the study. After 4-day incubation with 10(-6)M D3 or A, the HL-60 cells differentiated into monocyte-like (D3-HL-60) or mature granulocyte-like (A-HL-60) cells, respectively. They were then infected with L. pneumophila. Intracellular multiplication of the bacteria was evident in D3-HL-60 cells but not in HL-60 or A-HL-60 cells. D3-HL-60 cells required a 24-h infection time for the intracellular growth of L. pneumophila. D3-HL-60 cells activated with human recombinant IFN-gamma for 1-24 h (gamma-IFN-D3-HL-60 cells) before infection markedly inhibited L. pneumophila multiplication, the effect of IFN-gamma being dose dependent. Surface marker analysis was carried out in HL-60, D3-HL-60, and gamma-IFN-D3-HL-60 cells. On D3-HL-60 cells, CD11b, CD11c, CD14, and CD35 antigen increased, whereas CD71 and HLA-DR antigen decreased. This finding suggested that HL-60 cells differentiated into monocyte-like cells; the acquisition of the complement receptors, CD11b(CR3) and CD35(CR1), seemed to be important for phagocytosis and for the subsequent intracellular multiplication of L. pneumophila. The gamma-IFN-D3-HL-60 cells showed an increase of CD16, CD36, CD71, and HLA-DR antigen, suggesting that they were in an activated state. Our study indicated, first, that D3 can induce human leukemic cells to differentiate into functional monocyte-macrophage-like cells that can support the intracellular multiplication of L. pneumophila and, second, that these differentiated leukemic cells can be activated by IFN-gamma to markedly inhibit bacterial growth.
Animals↗
Protein profiles of Legionella pneumophila Philadelphia-1 grown in macrophages and characterization of a gene encoding a novel 24 kDa Legionella protein.
Legionella pneumophila Philadelphia-1 strain was grown in cultured macrophages of guinea pigs, hamsters, and A/J mice and the bacteria were purified by Percoll density gradient centrifugation without any detergent. Patterns of the bacterial proteins were compared by SDS-PAGE with those of organisms cultured in vitro. A 24 kDa protein was a major protein of intracellularly grown bacteria: its expression was about four times as much as a 24 kDa protein of agar-grown bacteria. At least three novel proteins (100, 65, and 16 kDa) that were not found on agar-grown bacteria were also observed. In this paper, we focused on the 24 kDa major Legionella protein expressed within macrophages. Western blot and N-terminal amino acid analysis revealed that this protein is a novel protein different from Legionella proteins previously reported, including a 24 kDa macrophage infectivity potentiator protein (Mip). On the basis of amino acid sequence (MQRIKKI and IANAQGK), two kinds of oligonucleotides were synthesized and radiolabeled. Using these oligonucleotides as DNA probes, a 7.2 kb EcoRI-digested DNA fragment encoding the 24 kDa protein was cloned into lambda ZAP II phage vector in Escherichia coli XL1-Blue. A 0.9 kb DNA fragment from the 7.2 kb fragment was further subcloned into pUC118 in E. coli CSR603 for maxicell analysis or XL1-Blue for DNA sequencing. Maxicells which carry recombinant plasmids consisting of the 0.9 kb DNA fragment and vector plasmid pUC118 expressed the 24 kDa protein. When the DNA fragment encoding the protein was sequenced, an open reading frame of 555 base pairs was identified. The inferred polypeptide had a molecular weight of 20 kDa and an estimated isoelectric point of 8.14. Both the nucleotide sequence and the deduced amino acid sequence were distinct from those of bacterial proteins reported previously, suggesting that the protein is a novel Legionella protein.
Amino Acid Sequence↗
Dextran sulphate enhancement of lipopolysaccharide-induced tumour necrosis factor-alpha production by murine peritoneal macrophages: correlation with macrophage blockade.
Proteose peptone-induced murine peritoneal macrophages (M phi) were preincubated with 100-800 micrograms/ml of dextran sulphate (DS) 500 (M(r) 500,000) or DS1000 (M(r) 1,000,000). After 2-24 h of the preincubation, the M phi were stimulated with 1 microgram/ml of lipopolysaccharide (LPS) in vitro for 18 h in DS-free culture medium. The culture supernatants were then collected for TNF assay. The LPS-induced TNF activity of M phi supernatant preincubated with DS500 or DS1000 for 6 h was enhanced by up to about ten-fold compared with those preincubated without DS. This enhancing effect was not observed when M phi were preincubated with 100-800 micrograms/ml of low molecular weight DS5 (M(r) 5,000) or neutral dextran (Dex) 500 (M(r) 500,000). The enhancement of LPS-induced TNF-alpha production from M phi was observed after 2 or 4 h of incubation with DS1000 or DS500, respectively. The phagocytic activity of M phi was determined in vitro by the ingestion index and phagocytic capacity using Saccharomyces cerevisiae. Treatment with DS500 or DS1000 significantly suppressed the phagocytic activity from 2 h after the incubation, but this suppression was not observed in M phi incubated with DS5 or Dex500. Our experiments indicate that DS500 and DS1000 act directly on M phi and enhance LPS-induced TNF-alpha production from M phi, and that the enhancement is closely related to the suppression of M phi phagocytic function.
Animals↗
Lipopolysaccharide and granulocyte colony-stimulating factor delay neutrophil apoptosis and ingestion by guinea pig macrophages.
In previous studies, neutrophil-ingesting macrophages were clearly and easily observed in the peritoneal cavity of guinea pigs after intraperitoneal injection of thioglycolate medium, and phagocytosis of neutrophils by macrophages could be detected in in vitro cultures of peritoneal exudate cells. Using an in vitro system, we examined the effect of bacterial lipopolysaccharide and recombinant human granulocyte colony-stimulating factor on the apoptosis (programmed cell death) of neutrophils and their subsequent ingestion by macrophages. Lipopolysaccharide delayed karyopyknosis and apoptosis of neutrophils, as shown by endogenous endonuclease activity and a high proportion of trypan blue-excluding cells, and subsequent ingestion by autologous macrophages. Granulocyte colony-stimulating factor also delayed neutrophil karyopyknosis and ingestion by macrophages. When a thioglycolate medium was coinjected intraperitoneally with lipopolysaccharide into guinea pigs in the in vivo system, delays in neutrophil disappearance and ingestion by macrophages in the peritoneal cavity were also observed. We suggest that bacterial products and cytokines regulate neutrophil apoptosis and subsequent ingestion by macrophages at inflamed sites.
Animals↗
[Progress and application of molecular genetics in the research of Mycobacterium tuberculosis].
In the last decade, a great deal of advances in the genetics of Mycobacterium tuberculosis have been made by the introduction of new genetic technologies. In this review, a brief discussion of the progress in mycobacterial genetics, especially, gene cloning, development of host-vector systems, structural analysis of chromosomal DNA, plasmid DNA and mycobacteriophage DNA, IS element, and drug resistance mechanism was presented.
Humans↗
Genetic and biochemical analysis of ribosomal proteins of minocycline-susceptible and -resistant Mycobacterium smegmatis.
A minocycline (MINO)-resistant mutant was isolated from Mycobacterium smegmatis strain Rabinowitschi. Polypeptide synthesis in the cell-free system prepared from the mutant was resistant to minocycline (MINO) because of alterated 30S ribosomal subunits. Upon two-dimensional gel electrophoresis, two proteins of 30S subunit were found to be altered. MINO resistance phenotype was transferred by mating to the recipient strain P-53. MINO resistance phenotype of a recombinant thus obtained was transferred by a different mating system to the recipient strain Jucho, once again. Ribosomal proteins of each of the donors, recipients and recombinants were analyzed and compared on 2-dimensional (2D) electrophoresis. Approximately 50 ribosomal proteins were observed in 70S ribosomes. Some proteins were differently electrophoresed in different strains. The 30S ribosomal subunits contained at least 19 proteins and 50S ribosomal subunits contained at least 23 proteins. Some proteins were easily washed off during dissociation of subunits in sucrose gradients. At least one protein (designated F) in both subunits was observed at the same position. One protein designated C in 30S subunits could be co-transferred to the recipient cells together with resistance phenotype at the frequency of 100% in the 30 recombinants examined so far. The other protein designated D in 30S subunits could be transferred at the frequency of 86-88%. Three other proteins in 50S subunits could be co-transferred to the recipient strain at a lower frequency. Minocycline resistance, therefore, could be mapped close to genes encoding the structure of ribosomal proteins in M. smegmatis.
Bacterial Proteins↗
Priming effect of dextran sulphates on lipopolysaccharide-induced tumour necrosis factor production in mice.
Dextran sulphate (DS) 500 (M.W. 500,000) is commonly used as a reticuloendothelial (RE) blocker. We found that lipopolysaccharide (LPS)-induced tumour necrosis factor (TNF) production in sera was enhanced when mice were pretreated with DS500. When mice were pretreated with DS1000 (M.W. 1,000,000), TNF activity in sera was also significantly enhanced by the LPS injection in comparison with the saline-treated group, but not by the pretreatment with the low molecular weight of DS5 (M.W. 5,000), neutral dextran (Dex) 500, or positively-charged diethylaminoethyl dextran (DEAE-Dex) 500. The enhancement of LPS-induced TNF production occurred from 2 h after DS500 pretreatment. Pretreatment with DS500 or DS1000 significantly suppressed the carbon clearance from the blood in mice from 2 h after DS injection, but this suppression was not detected by the pretreatment with DS5, Dex500, or DEAE-Dex500. We suggest that negative-charge and high molecular weight are essential for dextran derivatives to enhance LPS-induced TNF production, and that the enhancing effect of DS is closely related to the suppression of the RE function.
Animals↗
Investigation of the role of macrophages and endogenous interferon-gamma in natural resistance of mice against Legionella pneumophila infection.
Mice are highly resistant to Legionella pneumophila infection. To study the natural resistance, we used A/J and C57BL/6 mice which have macrophages permissive and non-permissive for the intracellular growth of L. pneumophila, respectively. The LD50 for A/J and C57BL/6 were 2.7 x 10(7) and 7.2 x 10(7) CFU, respectively, indicating that the difference in macrophage ability to regulate the bacterial growth had some effect on susceptibility to L. pneumophila. There was no difference between both strains in elimination of the bacteria from the blood stream within 5 h after infection. When mice were challenged intravenously with a sublethal dose (4 x 10(6) CFU), the bacterial burden in the liver at day 1 was significantly higher in A/J than in C57BL/6. The bacteria, thereafter, were eliminated rapidly from the liver at a similar rate in both strains. Elimination of the bacteria from the spleen and lungs was also delayed in A/J as compared to C57BL/6. Naive spleen cells of both strains in vitro could produce a large amount of interferon-gamma (IFN-gamma) one day after they were stimulated with formalin-killed L. pneumophila. When anti-murine IFN-gamma monoclonal antibody was administered, the bacterial burden in liver, spleen and lungs significantly increased in A/J, and also in C57BL/6 to some extent. We suggest that the innate macrophages' ability to regulate the intracellular bacterial growth and the endogenous IFN-gamma produced in a very early phase play a critical role in murine natural resistance against L. pneumophila infection.
Animals↗
Phagocytosis of polymorphonuclear leukocytes by guinea pig peritoneal macrophages: effects of serum and temperature in vitro.
The regulation of phagocytosis of neutrophils by peritoneal macrophages was studied in vitro. Peritoneal exudate cells (PECs) of guinea pigs were lavaged 15 h after the i.p. injection of thioglycollate medium and were cultured in chamber-slides. When PECs were cultured in RPMI 1640 medium in the absence of serum, approximately 20% of the macrophages phagocytized autologous neutrophils during 48-72 h of culture. Addition of guinea pig serum to the culture (2.5-20% v/v) suppressed the extent of the phagocytosis. The suppression was induced by globulin-rich ammonium sulfate fractions of the serum. Sera from rat, mouse, hamster, horse or calf also suppressed the phagocytosis, but fetal bovine serum (FBS) supported the phagocytosis, which was inhibited by globulin-rich Cohn fractions of bovine serum. The rate of neutrophil-phagocytosing macrophages was proportional to the rate of the pyknotic change of neutrophils. At a high temperature (42 degrees C), the autophagocytosis took place at 12 h of culture when fresh, but not heat-inactivated, autologous serum was added, implying that complement components may play a role in the hyperthermia-induced phagocytosis of neutrophils by macrophages. At 42 degrees C, ingested neutrophils did not show the pyknotic changes, indicating that intact neutrophils were ingested by macrophages.
Animals↗